- This topic has 3 replies, 4 voices, and was last updated 20 years, 6 months ago by SylvanLMP.
29 Jan 2001 at 4:17 pm #274530Adam Mersky
In plan on installing an add on coal fired boiler to my present gas fired boiler . I would like to know if I need an other pump between the two boilers. The present system has three zones , each with its own pump.
30 Jan 2001 at 2:57 pm #289912fourth yearParticipant
If you feed out of one boiler and return into the other one, and then tie the two boilers together, that will keep the temperature constant in both of them. Just be sure to have the necessary safety devices on the coal fired one, especially if it is going to be hand fired.
30 Jan 2001 at 4:31 pm #289913GuestParticipant
You do not want both boilers to be kept at the same temperature. When one boiler heats another boiler, the extra heat used to keep the other boiler up to temperature is wasted and lost from the non-operating boiler jacket and the flue.
By piping them in parallel, each boiler can contribute its own heat when it is in use. Through the proper use of flow control valves, you can have either boiler control its own circulator with little change in the existing piping.
By installing inlet and outlet valves and piping the boilers in parallel, you can repair either boiler without having to stop heating the home, as is done in commercial buildings.
31 Jan 2001 at 2:36 am #289914SylvanLMPParticipant
Well I Guess the helper again proves his incompetence AGAIN One of many
(Usual for him)
The real question whenever using duel fuels is the chimney connection.
Coal being sooty and Gas being a “dry heat” causes problem like causing sulfuric in the chimney and poof no more chimney lining
Coal being a dirty fuel also has to have the chimney not only cleaned more often BUT inspected.
Even when I install a duel fired system Oil and Gas I have certain codes that must be followed.
The heating piping Harold is completely right and the helper well what can I say he just doesn’t know any better (typical)
You had better check with your local building department for the chimney specifications AND find out how much MORE free air you may need using a coal fire as opposed to a “gas” type.
Mixing different fuel through the same chimney or combination breaching is not something that should be installed on a hit and miss application.
Contact your local professionals and for Pete’s SAKE don’t even think of allowing a non skilled non knowing helper within 500 ft of your home.
When in doubt read the NBBI and the AGA ( for flue piping) and the ASME section IV for piping arrangements.
I still would advise him to find another trade to dabble in.
He sure wont ever make it as a plummmmer
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